Gelatin is used as a binder of many silver halide photographic light-sensitive material. Generally, a silver halide photographic light-sensitive material (hereinafter referred to as simply light-sensitive material) has a silver halide emulsion layer, an intermediate layer, a protective layer, a filter layer, a subbing layer, an anti-halation layer, a UV absorbing layer, an anti-static layer or a backing layer on a support such as glass, paper, or synthetic resin film.
These various photographic constitution layers contain gelatin as a main component The photographic constitution layers, which are obtained by coating an aqueous solution containing a hydrophilic polymer and/or a water-dispersible polymer on a support, have a poor mechanical strength. For example, a gelatin membrane has lower melting point and extremely swells in water. A latex membrane has disadvantages in that its adhesion to a support is poor and it is likely to exfoliate.
It is well known that a compound called "hardener" is added to photographic structural layers to enhance mechanical strength thereof. For example, organic hardeners including aldehyde compounds such as formaldehyde and glutaric aldehyde, compounds having reactive halogen described in U.S. Pat. Nos. 2,732,303, 3,288,775, 3,951,940, British Patent Nos. 974,723 and 1,167,207, ketone compounds such as diacetyl and cyclopentadione, bis(2-chloroethyl)urea, 2-hydroxy-4,6-dichloro-1,3,5-triazine, divinylsulfone, 5-acetyl-1,3-diacroylhexahydro-1,3,5-triazine, compounds having a reactive olefin as described in U.S. Pat. Nos. 3,232,763 and 3,635,718 and British Patent No. 994,809, vinylsulfonyl compounds described in U.S. Pat. Nos. 3,539,644, and 3,642,486, Japanese Publication Nos. 49-13563/1974, 53-47271/1978 and 56-48860/1981, and Japanese Patent O.P.I. Publication Nos. 53-57257/1978, 61-128240/1986, 62-4275/1987, 63-53541/1988 and 63-264572/1988, N-hydroxymethylphthalimide, N-methylol compounds described in U.S. Pat. Nos. 2,732,316 and 2,586,168, isocyanates described in U.S. Pat. No. 3,103,437, azilidine compounds described in U.S. Pat. Nos. 2,983,611 and 3,017,280, acid derivatives described in U.S. Pat. Nos. 2,725,294 and 2,725,295, carbodiimides in U.S. Pat. No. 3,100,704, epoxy compounds described in U.S. Pat. No. 3,091,537, isooxazoles described in U.S. Pat. Nos. 3,321,313 and 3,543,292, halogencarboxylic aldehydes such as mucochlorolic acid, dioxane derivatives such as dihydroxydioxane and dichlorodioxane or inorganic hardeners including alum chromate, zirconium sulfate and chromium trichloride are cited.
However, the above-mentioned conventional hardeners, when used for a photographic light-sensitive material, have some shortcomings in that hardening effect is insufficient, there is long-termed change of the degree of hardness called after-hardening due to slow hardening effect on gelatin, an adverse affect (increase of fogging, reduction of sensitivity or maximum density or contrast reduction) on the performance of photographic light-sensitive material, loss of hardening effect due to other co-existing photographic additives and reduction of the effects of other photographic additives (for example, a coupler in coupler-in-emulsion type color emulsion).
As a hardener wherein hardening reaction on gelatin is relatively speedy and after-hardening is small, compounds having a dihydroquinoline skeleton described in Japanese Patent O.P.I. Publication No. 50-38540/1975, N-carbamoyl pyridinium salts described in Japanese Patent O.P.I. Publication Nos. 51-59625/1976, 62-262854/1987, 62-264044/1987 and 63-184741/1988, acylimidazols described in Japanese Patent Publication No. 55-38655/1980, compounds having 2 or more N-acyloxyimino groups in a molecule described in Japanese Patent Publication No. 53-22089/1978, compounds having an N-sulfonyloxyimide group described in Japanese Patent OPI Publication No. 52-93470/1977, compounds having a phosphor-halogen linkage described in Japanese Patent OPI Publication No. 58-113929/1983, and chloroformamidium described in Japanese Patent OPI Publication Nos. 60-225148/1985, 61-240236/1986 and 63-41580/1988 are known.
Among the above compounds, the N-carbamoylpyridium salts have high hardening speed and reduced after-hardening degree. However, an amine, which is a by-product produced after hardening reaction, has an adverse effect on light sensitive materials to the degree which is not disregarded.
To the contrary, the vinylsulfonyl compounds described above, which do not produce the by-product, are known. These compounds have reduced adverse effects on the light sensitive materials, but have shortcomings in lower hardening speed and low water solubility.
U.S. Pat. No. 5,411,856 discloses vinylsulfonyl compounds which these shortcomings are improved, but hardening speed is not yet satisfactory. Accordingly, a hardener which has higher hardening speed has been sought.